使用R中的循环创建50+国家/地区图

install.packages(c("ggplot2", "maps", "mapdata"))

library(ggplot2)
library(maps)
library(mapdata)

countries <- c("China", "United States", "India", "Indonesia", "Pakistan", "Brazil", "Nigeria", "Bangladesh", "Russia", "Mexico", "Japan", "Ethiopia", "Philippines", "Egypt", "Vietnam", "DR Congo", "Turkey", "Iran", "Germany", "Thailand", "United Kingdom", "France", "Italy", "Tanzania", "South Africa", "Myanmar", "Kenya", "South Korea", "Colombia", "Spain", "Uganda", "Argentina", "Algeria", "Sudan", "Ukraine", "Iraq", "Afghanistan", "Poland", "Canada", "Morocco", "Saudi Arabia", "Uzbekistan", "Peru", "Angola", "Malaysia", "Mozambique", "Ghana", "Yemen", "Nepal", "Venezuela", "Madagascar", "Cameroon")

map_data <- data.frame()

for (country in countries) {
  map <- map_data("world", country)
  map_data <- rbind(map_data, map)
}

ggplot() +
  geom_polygon(data = map_data, aes(x = long, y = lat, group = group), fill = "lightblue", color = "white") +
  coord_equal() +
  theme_void()